Deye inverter earthing and RS485 connection

[LouiseSJPP]

I have just installed my 5kW system, with Pylontech 5kWh battery. The Deye wiring diagram shows the battery as unearthed, but the battery instructions say earth it.

I have an earth rod for the house, no earth back to sub-station. I have connected all earths to this rod: house, panels, inverter, battery. Is this OK, or should the DC earths be separate?

There seems to be a suggestion that earth and neutral should connect at the inverter for an earth rod installation. I get lost in the terminology here around earthing. Is this right?

At the moment, the solar system is islanded, and driving some discrete loads in the house, isolated from the grid system. When I can find an electrician, the system will be zero-export grid-tied, and a V2H electric car will be added into the mix, with battery capacity for daily power storage.

For this, I'll need inverter monitoring. Not having wi-fi near the solar array (and, err, having lost the wifi dongle) I'm wondering if I can hook up an RS485 monitoring system, understanding that Deye's RS232 output is propriety. Can anyone advise?

Detail: location, northern Spain. Deye SUN-5K-SG03LP1-EU. Skillset: professional mechanical engineer.

[Liam]

Yeah this stuff gets confusing fast, especially when inverter and battery manuals don’t line up.

What you did with one earth rod and bonding everything (frames, inverter, battery case) sounds pretty normal. That part is usually fine. Where I’d be a bit careful is the DC side — most of these systems run a floating DC, so grounding the battery negative can sometimes cause weird issues depending on the inverter. I’d double check that before changing anything.

Same with neutral-earth bonding — some inverters handle it internally in island mode, so you don’t want to accidentally double it. RS485 should work though, and honestly it’s more reliable than WiFi anyway if you can access it.

Sounds like a solid setup overall